The Pre-Main Sequence Binary W134: 1994 Observations and Analysis
Session 48 -- Young Stars
Display presentation, Tuesday, 10, 1995, 9:20am - 6:30pm

## [48.21] The Pre-Main Sequence Binary W134: 1994 Observations and Analysis

Deborah L. Padgett (IPAC), Karl R. Stapelfeldt (JPL), Jon A. Holtzman (Lowell Observatory)

We present the results from further investigations of the pre-main sequence double-lined spectroscopic binary W134. Spectroscopic observations in 1994 with the Palomar 1.5m echelle have enabled us to refine the orbital parameters of the system and to pinpoint times for potential eclipse events. Using the improved ephemeris, we obtained relative photometry at the Lowell 42-inch telescope during a predicted eclipse time. Regrettably, these data confirm the absence of any significant dip in the B and I light curves of W134 to an accuracy of $\pm$ 0.03 magnitudes during 5.5 hours of observation. The lack of eclipse in a system which is both very young and highly inclined places important constraints on PMS tracks. Using revised estimates of the stellar luminosities, we find that the absence of eclipse requires the inclination angle to be less than 77$\deg$ $\pm$ 3$\deg$. This in turn imposes a lower limit on the total mass in the system of 3.3 M$\sun$. When the components of W134 are placed on the HR diagram, the mass constraint tends to favor the higher masses predicted by the Swenson et al. (1994) PMS tracks, although the D'Antona and Mazzatelli (1994) tracks are not ruled out.